1. Field of the Invention
The present invention relates generally to casing valves for use in wells, and more particularly, but not by way of limitation, to a casing valve adapted for use in substantially non-vertical deviated portions of wells.
2. Brief Description of the Prior Art
It is known that sliding sleeve type casing valves can be placed in the casing of a well to provide selective communication between the casing bore and subsurface formations adjacent the casing valve. One such casing valve is shown in U.S. Pat. No. 3,768,562 to Baker, assigned to the assignee of the present invention. The Baker '562 patent also discloses a positioning tool for actuating the sliding sleeve of the casing valve.
U.S. patent application Ser. No. 231,737 to Brandell, and also assigned to the assignee of the present invention, discloses the use of sliding sleeve casing valves in a deviated portion of a well. One embodiment of the Brandell device utilizes an aluminum plug in the housing of the casing valve which can be removed by acid washing.